Teledyne T100, Инструкция по эксплуатации, Страница: 228 / 404

Theory Of Operation Teledyne ML - T100 UV Fluorescence SO2 Analyzer
228 06807A(DCNxxxx)
9.1.7.2. PMT OPTICAL FILTER
The PMT used in the T100 reacts to a wide spectrum of light which includes much of
the visible spectrum and most of the UV spectrum. Even though the 214 nm light used
to excite the SO
2
is focused away from the PMT, some of it scatters in the direction of
the PMT as it interacts with the sample gas. A second optical band pass filter placed
between the sample chamber (refer to Figure 9-2) and the PMT strips away light outside
of the fluorescence spectrum of decaying SO
2
* (refer to Figure 9-5) including reflected
UV form the source lamp and other stray light.
LAM
P
OU
T
P
UT
(Ar
b
it
ra
ry
U
n
tis
)
10
5
10
4
10
2
10
3
10
1
1
100 200 300 400 500
WAVELENGTH (nm)
0
2
1
3
.9
3
3
0
.3
SO
2
* FLUORESCENT
SPECTRUM
PMT OPTICAL FILTER
BANDWIDTH
Figure 9-5: PMT Optical Filter Bandwidth